1. Field of the Invention
The present invention relates to gaming machines and, in particular, gaming machines such as slot machines incorporating a bonusing game.
2. Statement of the Problem
It is well known in the gaming industry that bonus games attract and keep players at a gaming machine. The bonus game is typically another gaming machine or a random selection device which is enabled by a bonus qualifying signal from an underlying or primary gaming machine. A wide variety of bonus games, features, and devices are known some of which are set forth next.
The conventional WHEEL OF GOLD (trademark) and WHEEL OF FORTUNE (trademark) slot casino games incorporate a single play bonusing feature. A rotating wheel is activated by the player depressing a bonus spin button when certain indicia appears on the reels of the slot game and is used to award bonus payouts in a spin of the wheel. A separate multiplier may be used to multiply the bonus payouts. After the bonus spin, play resumes in the underlying gaming machine. These games are commercially available from Anchor Gaming and are disclosed in U.S. Pat. Nos. 5,823,874 and 5,848,932.
In EP 0 874 337 A1, xe2x80x9cGaming Machine with Bonus Modexe2x80x9d published Oct. 10, 1998 and owned by WMS Gaming, Inc., a bonus game involving multiple plays is presented for an underlying gaming machine such as a slot machine. Here a Bernoulli trial procedure is used to allow a player to repeatedly play a high odds bonus game (such as another slot game) and receive awards until a losing combination occurs (i.e., winning until losing). The hit rate in the bonus game is greater than 50% (preferably higher than 70%) which results in a much lower hit rate in the underlying game. This hit rate difference causes the player to endure the low hit rate of the underlying slot game in order to qualify for the high hit rate of the bonus game. The length of the bonus game is longer when the hit rate for the bonus game is higher. This bonus feature allows a player to win each bonus game and collect winnings until the player receives a losing combination (i.e., losing until winning). This is a variation of WMS Gaming""s earlier bonus feature trademarked JACKPOT STAMPEDE which allowed the player in the bonus game to continually spin the bonus reels until receiving a winning combination. The recognized shortcoming with this earlier bonus feature was that the player""s expectation of receiving meaningful bonus awards is crushed since the first winning combination to be hit is statistically a small award (i.e., a cherry). Other high odds and xe2x80x9cwin till you losexe2x80x9d bonus games are found in UK Patent Application GB 2 180 087 A published Mar. 18, 1987 and GB 2 084 371 A published Apr. 7, 1982.
U.K. Patent Application GB 2 222 712 A published Mar. 14, 1990 sets forth a slot machine main game interconnected with a slot machine secondary game. The player has the option of pushing button 18 which debits his credit meter by the appropriate amount to play the secondary game such as another slot game. Hence, the player gambles an amount in order to play the bonus game.
U.S. Pat. No. 5,393,057 pertains to an electronic gaming apparatus and method therefor wherein each play in the bonus is the result of successive underlying game play. The invention teaches the use of an electronic primary gaming device such as a poker or a slot machine and an electronic secondary gaming device based on bingo. When a winning combination such as three queens appears in the primary game, a space in the bingo matrix is turned over to reveal a bingo symbol. Play continues on the primary game until a winning sequence occurs in the bingo game. The right to play the bingo secondary game does not occur unless the player inserts three or more coins into the primary game. Play continues until the game achieves a bingo in which case the player receives a prize. UK Patent Application GB 2181 589 A published Apr. 27, 1987 pertains to a slot machine having a jackpot feature whereby the prize value is transferred between separate jackpot displays as successive games are played. Some of the reel symbols are overprinted with a number and when that number lands on the payline, it is used to climb a ladder. The ladder enables the player to obtain one or all of the prizes in the upper portion of the slot machine. For example, if the overlaid number lands the player on a first playing level, then the player receives all three prizes. If the overlaid number lands the player on a second level, then the player can select which one of the three prizes to receive. If the player lands on a third level, then it becomes a game of skill to select which of the three prizes he selects. Finally, if the player lands on a fourth level, then the prize is randomly selected. The prize may also be randomly doubled. U.S. Pat. No. 5,560,603 sets forth a plurality of slot machines interconnected to an electronic controller which displays a separate race game. Each time a particular predetermined combination of indicia appears in the display of a particular slot machine, a signal is generated from the slot machine which advances the racing element through a particular predetermined distance. If the player""s horse reaches the finish line before a timer display times out, then the slot player wins an additional prize. The players in this patent are not racing against each other, but against a clock.
A former popular television game show trademarked THE JOKER""S WILD by Jack Barry Productions, Inc., permitted a player at the end of the show to play a giant slot machine until reaching a predetermined level of winnings, stopping with a lesser level of winnings, or being forced to stop (and losing everything) when a special symbol appeared on one of the three slot wheels. In the conventional THE JOKER""S WILD slot machine, the special symbol was a picture of a xe2x80x9cdevil.xe2x80x9d
A need exists to adapt the excitement created by such the aforesaid television game show through continued play of a bonus gaming machine such as a slot machine with the expectation of additional accumulation to an underlying gaming machine, but with the danger of losing all accumulated winnings. A need exists to provide a riskless initial award to the player upon entering the bonus game which cannot be lost in the bonus game. A need exists to provide a bonus feature for an underlying game that allows the operator to control the length, player enjoyment and player involvement in the bonus mode so that the bonus game doesn""t have to be an automatic xe2x80x9cwin until a losexe2x80x9d or xe2x80x9close until a winxe2x80x9d occurs.
1. Solution to the Problem.
The present invention solves the above needs by providing adjacent gaming machines where the first gaming machine plays a conventional slot gaming machine and the second gaming machine provides the bonusing feature also in a slot gaming machine. In one embodiment, all of the accumulated winnings may be lost during bonus game play. A player, in one embodiment, entering the bonus game is initially awarded a riskless value. The design of the bonus game allows the operator to control the length of the bonus game and the player involvement and enjoyment therein.
2. Summary.
The present invention provides two adjacent gaming machines. In the preferred embodiment, the gaming machines are slot machines and each slot machine employs physical reels with stops that are equally likely to happen and wherein each reel has a predetermined number of stops. In the primary slot machine, a bonusing qualifying event is used to enable a player to play the secondary slot machine containing the bonus game. The bonusing game on the secondary machine proceeds in a cumulative fashion with the player stopping when special xe2x80x9closexe2x80x9d or xe2x80x9cstopxe2x80x9d play symbols appear on the payline, when the player issues a stop signal, when a predetermined amount of winnings occurs, when a predetermined number of spins occurs, or any combination thereof.
A method is set forth for playing a bonus game in a secondary slot machine adjacent a primary slot machine. The secondary slot machine has a number of reels and a payline. The primary slot machine issues a bonus qualifying signal to the secondary slot machine to start play of a bonus game when a bonus qualifying event occurs. The method of the present invention randomly spins the reels in the secondary slot machine. The reels include value symbols and end game symbols which may be of two basic types: a lose game symbol and a stop game symbol. After the random spin, the values of any value symbols displayed on the payline of the secondary slot machine are accumulated into an accumulated winning value. The value symbols could include positive integer values, negative integer values, and multiples. The random spinning, determination of values of any value symbol and the accumulation of winning values is repeatedly continued until an end of the bonus game occurs. The end of the bonus game can occur in a number of ways. In one embodiment, a predetermined number of bonus game end symbols are afforded the player to be obtained during play of the bonus game. If the predetermined number is one, then the bonus game ends upon the first occurrence of an end symbol. When the predetermined number is greater than one, the number of end game symbol appearances on the payline are counted and when the predetermined number is reached, the bonus game is over. When the end game symbol is a stop game symbol, the bonus game stops when the stop symbol appears on the payline and the accumulated winnings are awarded to the player. When the end game symbol is a loss symbol, all or a portion of the accumulated winnings is retained by the operator of the game. The player has the option in some versions of the bonus game to issue a stop signal in the case of an end game symbol being a lose symbol and, if the player issues a stop signal before the predetermined number of game symbols is reached, then the player is awarded the accumulated winnings value. Under the method of the present invention, and in some embodiments, an initial riskless value is immediately awarded the player upon the issuing of the bonus qualifying signal so that the player is awarded regardless of the outcome of the bonus game.
In another version of the bonus game of the present invention, the symbols include null symbols which allow the operator of the bonus game to control the length of the bonus game by having the results of random spins containing no value symbols.
The method of the present invention under one version ends the bonus game when the accumulated winnings value equals or exceeds a predetermined winnings value which provides protection to the operator against a player who continues to win all random spins.
In other versions of the method of the present invention, the player has the opportunity to purchase lose symbols with available credits in the accumulated winnings value obtained during the bonus game to lengthen the bonus game for the player in the hopes of accumulating even more bonus awards. The purchased lose symbols allow the player to reduce the current count of lose symbols towards the predetermined number. In a variation of this, the player in playing the underlying game can acquire lose symbol credits which can be similarly used in any resulting bonus game.
In a variation of the method of the present invention, a player who continually avoids the end of the bonus game and who reaches a certain count value of spins in the bonus game automatically receives an overall jackpot award. Likewise, a limit value can be set into the bonus game to prevent the player from playing beyond a certain number of spins and when the number of spins equals the limit value, the bonus game ends and the player is awarded the accumulated winnings value.
All of these features alone or in combination with each other allow the operator of the bonus game of the present invention to control the length of time the bonus game occurs, control the player excitement and enjoyment of the game, and provide player interaction with the bonus game.